Been finding some good deals on 2.5 disks lately, but have never bought one before. Have a couple of 3.5 disks on the other hand in my Unraid server. Wondering how much it matters wether I get a 2.5 or not? What form factor do you prefer/usually go for?
3.5" are cheaper, go up to higher capacities (2.5" maxes out at only 5TB IIRC), and are easier to find cheap in used/refurb formats.
I wouldn’t use 2.5" unless you absolutely had to for some reason.
The 2.5" drives are significantly more power efficient, often by a factor of 10. They also tend to be less noisy and produce less heat.
So in a small form factor NAS that isn’t under heavy load, 2.5” drives are usually the better option.
It looks like about 2-3W with 2.5" vs 6-8W with 3.5"
So 3.5" drives are going to be more efficient, since you can get one that’s 4x the capacity (20TB vs 5TB) for only a little over double the power usage.
Less noise is definitely a bonus if your NAS sits next to your workstation or something though.